move HDFS-4657 to branch-2.2.1

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1536887 13f79535-47bb-0310-9956-ffa450edef68
YARN-1068. Add admin support for HA operations (Karthik Kambatla via bikas)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1536888 13f79535-47bb-0310-9956-ffa450edef68
Fix inadvertent file changes made via r1536888 (bikas)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1536894 13f79535-47bb-0310-9956-ffa450edef68